1. FIELD OF THE INVENTION
The present invention relates to the field of drilling means, and more specifically, to a flame jet tool for drilling holes in the ground at great depths.
2. PRIOR ART
Excavation means, and more specifically excavation means utilizing a jet-type of instruments are well known in the art. One such type of system is disclosed by Ross, U.S. Pat. No. 3,152,651. In the Ross apparatus, an elongated member is lowered into the ground whereupon a steam jet nozzle is activated. Activation of the nozzle causes the steam to act upon the ground in such a manner that chunks of material are gorged out of the ground. The pressure from the steam jet nozzle also sends these chunks crashing about to further strike and break up the surface adjacent the jet nozzle. It should be noted, however, that such device, while perhaps useful for forming holes a relatively short distance, is not particularly adapted for drilling at great depth. Moreover, while such steam jet nozzle may be able to work under certain soil conditions, many types of hard solid rocks are not easily broken up by such a system.
Another type of device is disclosed by Fleming, U.S. Pat. No. 3,045,766. In the Fleming device a blow pipe is lowered into the earth which contains a rotating burner adjacent the bottom thereof. Fuel and oxygen are supplied to the burner and the flames emitting therefrom are used to melt holes in the ground. While such a system has proved to be useful in a wide range of different rocks and soil, there is no means indicated that would enable such a device to be used when drilling at substantial depths.
Yet another type of device is disclosed by Elmore, U.S. Pat. No. 3,620,313. In the Elmore device a liquid propellant is burned and is pulsed to produce high combustion pressure with large power outputs. The device comprises an upper part and a lower part. The upper and lower parts are connected through a gimble mount to permit articulation of the lower part with respect to the upper part. While such device is disclosed as being adaptable for drilling at great depths, there is no disclosure of means for controlling the articulation of the lower part or for raising or lowering the lower part so as to further increase the controllability thereof.
The problems of drilling at great depths are recognized in the art. For example, pressure systems which could be used for drilling near the surface of the earth present major problems when the same type system is used to drill at great depths, i.e., depths exceeding 100 meters. This depth in the earth surface produces problems in the ability to pump fluids from the surface to the drill bit. While many such systems have been evolved to enable this pumping to take place, uneven burning due to uneven amounts of fuel being supplied to the drill bit has resulted. Recently, self-contained drilling members have been used. Such self-contained members are usually lowered into the ground by a cable. However, even with these new systems, when depths of greater than 100 meters are encountered, it is difficult to control the action of the drill bit especially when such bit is suspended from a cable which in turn must also be at least 100 meters in length. The prior art devices, including those discussed hereinabove, all use a variety of suspension cables to lower the drill bit into the well hole so as to enable the bit to cut through the ground and thereby extend to the crust of the earth. While such systems may work in certain type of rocks and for relatively shallow holes, the present invention represents improvements in the ease with which such holes are extended to great depth such as, for example, 10,000 meters, as well as the simplicity of operation.
Yet another problem associated with such prior art devices is the fact that in forming holes in particularly hard materials, the need to rotate the drill bit as well as to carry the material which has been blasted out of the hole away from the area has been found to be necessary. The above prior art devices discuss no means to accomplish this. By the use of the device of the present invention, such shortcomings are overcome and an effective solution is thus presented. This is achieved by coupling debris containers to the lance-and-guide shaft combination. Such debris containers prevent the substantial downward movement of loose particles.
While the present invention is particularly useful in extending oil well holes, it can also be used to form holes in exceedingly hard materials such that blasting material may be placed down into such holes so as to loosen the earth and thereby rendering it substantially more removable. Thus, the present invention finds utility in the oil well field as well as in the mining field.